Well, if you want them and you are willing to use console commands, press Control + Shift + J and copy-paste:
SugarCube.State.active.variables.truls = undefined
SugarCube.State.active.variables.cassius = undefined
Just be sure you have only one of each or it might brick something. Save to disk beforehand.
Yes. It adds to the dice roll.
Without dojo vs with dojo fully upgraded:
View attachment 3557060
Wiki is down for me so I cannot check if the dojo provides other benefits like raising the Household efficiency stat like how the gazebo raises Household contentment stat. Maybe not.
The Manhunter trait must be picked from the very start. I am not sure if you can console command it. It should be
SugarCube.State.active.variables.mctraitman = 100
Not sure if it works correctly though. If you want to try it, save to disk beforehand to have a backup.
He said something about a Mastersphere content for 0.8.3.3. There's also an upcoming Master Traits mechanic. The wiki is down for me right now but it provides sizeable buffs you can always earn in-game. For example, the master of war raises your damage with any weapon by +20 but you need to have a high melee, ranged, and other stats to get it. I forgot the exact numbers. If you can access the wiki, the page is called Master Traits.